BH-N18 Broadband Notch Filter
Double-pass notch filter passing vivid violet (400 – 460 nm) and bright red (570 – 780 nm) while plunging green-cyan light below 1 % for a crisp magenta spectrum.
- Violet passband: > 90 % T @ 400 – 460 nm
- Deep notch: < 1 % T @ 470 – 518 nm
- Red passband: 570 – 780 nm, 92 – 94 % T
- Red plateau: Ripple ≤ ±2 % keeps colour flat
- Construction: Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick
- Custom options: Ripple smoothing, AOI tuning, rapid prototypes
Learn more
BH-N18 sends two bright bands—one in the near-UV/violet
(≈ 400 – 460 nm) and one in the visible red-to-deep-red region (≈ 570 – 780 nm)—
while driving the green-cyan zone down to detector noise. Transmission peaks
around 90 – 94 % through each passband, drops below 1 % from ~470 nm to 518 nm,
then vaults back above 90 % by ~570 nm and stays flat out to ~780 nm before a
gentle near-IR taper.
KUPO coats Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG substrates
cut to any outline—from 5 mm chips to 450 mm plates—with thicknesses
of 0.21 – 3.8 mm, and can ship prototypes in about two weeks.
Typical uses: violet-excite/red-detect fluorescence, magenta stage lighting,
UV + red machine-vision illumination, green-band suppression in Raman or
multispectral sensors, and AR/HUD optics that need violet tracking plus red
graphics without mid-visible clutter.
Description
BH-N18 transmits two bright windows—one in the near-UV/violet (about 400 – 460 nm) and one spanning the visible red into the deep red (roughly 570 – 780 nm)—while it drives the entire green-cyan band down to detector noise. Transmission peaks around 90 – 94 % across each passband, plunges below 1 % from approximately 470 nm to 518 nm, then vaults back over 90 % by ~570 nm and stays flat to the end of the measured range. The result is a clean magenta spectrum with mid-visible clutter neatly suppressed.
Key advantages
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Deep 470 – 518 nm notch – < 1 % T removes green autofluorescence and ambient glare.
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High dual passbands – > 90 % T in 400 – 460 nm and 570 – 780 nm keeps violet excitation and red detection bright.
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Flat red plateau – Ripple constrained to ±2 % ensures uniform colour and signal strength.
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Hard-oxide durability – Ion-assisted coating survives heat, humidity, solvents, and repeated cleaning.
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Custom formats – Round, square, or free-form blanks from 5 mm to 450 mm, thickness 0.21 – 3.8 mm, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG glass.
Typical applications
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Fluorescence microscopy & flow cytometry – Pass violet excitation and red emission while silencing green background for higher contrast.
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Raman & multispectral sensors – Block 532 nm / 561 nm laser lines yet keep violet and red Stokes or anti-Stokes bands.
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Stage & architectural lighting – Produce saturated magenta washes (violet + red) with negligible green spill.
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Machine-vision systems – Combine UV flaw detection with red contour lighting, eliminating mid-band reflections.
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AR / HUD optics – Inject violet tracking beams and red graphics while keeping the central visible band dark to the eye.
Need prototypes in days or production volumes next quarter? BH-N18 filters can be coated, diced, and shipped to your exact specifications—fast.
